In conventional rack-mounted computer systems, a number of substantially planar electronics modules are arranged in horizontal or vertical planes extending from a front face of the rack to a rear face thereof. The modules are all connected to a vertical back plane by means of connectors arranged on a back edge of each module mating with co-operating connectors on the backplane. Installation and removal of individual modules from the system is effected by moving the modules in a horizontal direction towards or away from the backplane to connect or disconnect the connectors. The modules are received in horizontally-extending guides to ensure correct alignment and support for the modules.
The components of the electronics modules generate heat when they operate, and in order to remove this heat cooling air is caused to flow over the electronic components of the modules, with air being drawn in at one side of the module and expelled at the opposite side. The cooling air flows are preferably arranged to be in the same direction for all of the modules of the system, so that heated air expelled from one module is not drawn into a neighbouring module. Since a typical installation of a rack-mounted system will comprise a plurality of racks situated side-by-side, the direction of the cooling airflow is usually arranged to be from the “front” of the system to the “back”. The vertical backplane, however, presents a barrier to such a cooling airflow and necessitates a change in airflow direction, which reduces cooling efficiency.
An improved front-to-back airflow is achieved by arranging the modules in vertical planes extending from front to back relative to the supporting structure in the rack-mounted system, with the interconnection of the modules being made by a horizontally arranged “baseplane” rather than a vertically arranged backplane. The front to back cooling airflow thus runs parallel to the plane of the baseplane, and heated air can be expelled from the back of each module without having to change direction to exit the system.
Mounting the baseplane in a horizontal orientation however requires the insertion and removal of modules from the system to be effected by moving the module vertically rather than horizontally to connect it to and disconnect it from the baseplane. For the modules to be insertable and removable with a single linear movement relative to the system supporting structure, the modules may be guided in vertical guides relative to the supporting structure, but to prevent the module from falling during insertion or removal an operative must support the weight of the module during insertion and removal procedures. The modules may weigh several kilograms, typically from 5 to 15 kg, and may have to be lifted or lowered at arm's length.
The modules and their exposed connectors are easily damaged if dropped, and the baseplane of the system may also be damaged if a module is dropped during insertion and falls on to the baseplane.
The present invention seeks to provide a motion control device and a modular assembly for housing a computer system which comprises the motion control device, and modules for an assembly, for controlling the movement of detachable modules relative to the supporting structure of the modular assembly.